I feel like I want to have an egg, but, I didn't get an egg. So, if it's possible for you, type an answer below.
The only way to get an egg in Sword and Shield is to hatch one at the Daycare. This involves using two Pokemon in the same egg group or one Pokemon and a Ditto. If you put ditto and the Pokemon in the daycare they will always make an egg of the Pokemon that is not Ditto.
If you breed two Pokemon that aren't Ditto, then they will make an egg most of the time. There are three steps.
Make sure that you put a Male and a Female together.
After you deposit them into the daycare, talk to the lady outside and she will tell you if they are getting along. If it says they are not getting along, then an egg will not appear. This will only happen if the Pokemon are not Ditto.
Hop on your bike and ride around for a while. Soon, the daycare lady will have her hand to her face, which means you can get an egg.
There are several different chances to get an Egg, based on how compatible your Pokemon are. Use this Bulbapedia link to show them all (it assumes you have Oval Charm, which can be obtained in Circhester).
Hope I helped!